Out recently in Notes & Queries is a short article by me on antedating rates in the OED since revision started in 2000:Antedating (in) the Oxford English Dictionary
The article is OA, and linked in .pdf above.
One last thing I came across while writing the article is the following new sense s.v. ANTEDATING in OED3:
If something about the final quot seems off to you, it’s probably because the Jürgen Schäfer in question at the end has been excerpted in Hartmann’s sourcebook from 2003. The original is in Shäfer’s own 1980 monograph (which I quote in my article). Not sure how an OED researcher could have missed that one, but anyhow now I’ve antedated the postdating of ANTEDATING!